1. Field of the Invention
The present invention relates to a data processing apparatus and a data processing method for dealing with an incidental interruption of power supply in a system.
2. Description of Related Art
Conventionally, if an incidental interruption of power supply occurs in a system controlled by a computer, recovering has been done either by restarting from a completely initial stage or by hibernation, in which contents of the memory during operation before the interruption (or, blackout) are read out and execution of operations are resumed.
However, restarting presents a problem that carrying out all processes, such as detection of devices, initialization and the like typically required long time to perform. On the other hand, in the case of the hibernation, memory information is written out irrespective of a program under execution and amount of busy memory, thus causing a problem that it took long time to store the memory condition as data as well as to recovering it. Moreover, hibernation has a problem that it cannot be executed in the background during processing and it cannot cope with the incidental interruption of power supply.
Conversely, as a method of coping with the incidental interruption of power supply such as a sudden blackout or the like, there is a method of detecting a low voltage condition and then instructing an application to end processing. However, such method requires a circuit for detecting the voltage status condition. Thus, such method has a problem in which even if the circuit for detecting the voltage condition is installed, a system software program cannot assure whether all data can be stored in time until the interruption of power supply after the generation of the low voltage condition.
However, as this method having been used as a measure against power supply interruption, so that for a case of recovering the system, this method is carried out perfectly similarly to restarting or rebooting. Hence, this has a problem that it takes a long time for recovering to an operable condition.
Therefore, the present invention has been conceived so as to provide a data processing apparatus and a data processing method, in which, even if an incidental interruption of power supply occurs in a system, it can immediately return back to a status immediately before the interruption of power supply.